Potassium is not as well known as mineral nutrients such as calcium, iron, zinc and selenium, but this does not mean that it is not important. You know, potassium is an essential nutrient for our human body and can be said to be the guardian angel of the cardiovascular system. The serum potassium concentration of normal people is 3.5 ~ 5.5 mmol/L, and lower or higher than this concentration will be harmful to health and even fatal.
Participate in the metabolism of sugar and protein. When glucose and amino acids cross the cell membrane and enter the cell to synthesize glycogen and protein, there must be an appropriate amount of potassium ions.
Maintain normal osmotic pressure and acid-base balance of cells. Potassium is the basis of osmotic pressure in intracellular fluid, which can be exchanged with extracellular H+-Na+ through cell membrane to regulate acid-base balance.
Maintain neuromuscular pressure. The combined action of intracellular potassium ions and extracellular sodium ions can activate Na+-K+-ATPase and generate energy.
Maintain the normal function of myocardium. The concentration of potassium ions inside and outside myocardial cells is closely related to the autonomy, conductivity and excitability of myocardium. When potassium is deficient, myocardial excitability increases; When potassium is too high, myocardial autonomy, conductivity and excitability are inhibited, which can cause arrhythmia.
Relationship between potassium and cardiovascular diseases
When the total amount of potassium in the body decreases, when the concentration is lower than 3.5mmol/L, it can cause potassium deficiency, arrhythmia due to the increase of myocardial excitability, and even death due to ventricular fibrillation in severe cases.
When the total amount of potassium in the body is too much, hyperkalemia can occur when the concentration is higher than 5.5 mmol/L. The main influence on the cardiovascular system is that the myocardium is inhibited and the myocardial tension is reduced, so bradycardia, heart enlargement, weakened heart sounds and arrhythmia will occur, but heart failure will not occur.
Studies have shown that in general, taking 10mmol(388mg, equivalent to the potassium content of a cup of skim milk) of potassium every day can reduce the risk of stroke by 40%.
Two large-scale international studies on dietary sodium and potassium intake and blood pressure by INTERSALT and PURE also found that the higher the potassium content in food, the lower the risk of hypertension and stroke. Increasing the intake of potassium in food can reduce blood pressure, and increasing 60mmol potassium every day can reduce systolic blood pressure by 4.4mmHg.
Which foods are rich in potassium? How should I eat?
The Reference Intake of Dietary Nutrients for Residents in China (20 13) recommended that the suitable daily intake (AI) of potassium for adults is 2000mg, and the recommended intake (PI) is 3600mg.
Both plants and animals contain potassium, which mainly exists in ionic state, so the potassium needed by our human body mainly comes from these plants and animal foods.
Vegetables and fruits are the best sources of potassium, and cereals, bran, red beans, dried apricots, broad beans, lentils, mushrooms, soybeans, bamboo shoots, fish and laver are also foods rich in potassium.
It should be noted that
Potassium content in different parts of food is different. Potassium in food is concentrated in chaff and muscle, and potassium is easily soluble in water. That is to say:
The potassium content in flour and rice is lower than that in coarse grains.
The potassium content of peeled fruit is lower than that of peeled fruit.
The potassium content of fat meat is lower than that of lean meat.
The potassium content of canned fruits and vegetables or boiled fruits (excluding soup) is lower than that of fresh fruits.
Concentrated vegetable soup, fruit juice and broth all contain a considerable amount of potassium (but the purine content of broth is also high)
If you don't eat or eat less fresh vegetables and fruits in your daily diet, there is a risk of potassium deficiency.
Therefore, it is suggested to follow the dietary guidelines and balanced dietary pagoda of China residents, eat more fresh vegetables and fruits, and ensure proper potassium intake, so as to protect the cardiovascular system.